Bacteria That Make Sewage Smell Sweeter

In-Pipe Technology Co., a Wheaton (Ill.) sewage treatment company, has developed a technique for breaking down waste as it flows from bathrooms and kitchens to water-treatment facilities. The company's new system continuously introduces a patented blend of sewage-eating bacteria through a series of pumps in the sewer lines. In-Pipe President Daniel R. Williamson Jr., a microbiologist, says the populations of bacteria that produce the noxious odors from sewage are gradually overwhelmed by his blend of "good" bacteria. By the time wastewater reaches a treatment plant, fecal matter and other suspended solids have been reduced by as much as 60%.

Not only does that help boost treatment-plant efficiency, but the beneficial bugs help prolong the useful life of the plants and sewer lines. According to a report by the Water Infrastructure Network, a coalition of municipal agencies, the cost of upgrading and replacing aging wastewater systems to meet the mandates of the Clean Water Act will reach nearly $1 trillion over the next 20 years. The "wild" bacteria in sewage produce hydrogen sulfide, a gas that is corrosive as well as the source of that rotten-egg smell. But the only by-products of In-Pipe's secret mix are water, nitrogen, and carbon dioxide.

So why hasn't anybody tried this approach before? Williamson says In-Pipe was the first to figure out how to grow large quantities of good microbes cheaply, and deliver them continually inside pipelines. A demonstration project is planned this year near Washington, D.C.

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